Spin transfer switching in the nanosecond regime for CoFeB/MgO/CoFeB ferromagnetic tunnel junctions

摘要

Detailed spin transfer switching properties in the nanosecond region for CoFeB/MgO(001)/CoFeB magnetic tunnel junctions are reported. The switching current (I_C) was greatly increased in the <10 ns region. This characteristic resembles that of current-perpendicular-to-plane giant magnetoresistance (CPP-GMR), although both the junction geometry and resistance differ from those of a CPP-GMR device. We discussed the switching properties considering the contribution of high frequency loss and the theoretical limitation of the analytical model. Furthermore, we observed real-time switching in the nanosecond region. Using these results, we discuss the spin transfer switching mechanism in the nanosecond region with both adiabatic and thermally activated models.